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| Egernia gillespieae
Thorn, Hutchinson, Archer & Lee, 2019
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ABSTRACT
The Egerniinae (formerly the Egernia group) is a morphologically diverse clade of skinks comprising 61 extant species from eight genera, spread across Australia, New Guinea, and the Solomon Islands. The relatively large size and robustness of many egerniines has meant that they fossilize more readily than other Australian skinks and have been more frequently recorded from paleontological excavations. The Riversleigh World Heritage Area of northeastern Australia has yielded multiple egerniine fossils, but most are isolated jaw elements, and only one taxon (‘Tiliqua’ pusilla) has been formally described. Articulated remains recently recovered from the mid-Miocene AL90 site (14.8 Ma) at Riversleigh are here described as Egernia gillespieae and represent the first opportunity to describe the morphology of a significant portion of a single individual of a fossil member of the Egerniinae. We include this fossil and ‘T.’ pusilla in an integrated analysis of morphology and published molecular data to assess their relationships and to provide calibration points for the timing of the egerniine radiation. Our calibrated tree combining molecular and morphological data suggests that the modern Australian radiation dates to the end of the Eocene (34.1 Ma). Both fossils are within the Australian crown clade Egerniinae: Egernia gillespieae is placed close to species of the living genus Egernia, whereas ‘Tiliqua’ pusilla likely sits basal to the divergence of the clade inclusive of Tiliqua and Cyclodomorphus. The fossils thus provide direct evidence that the Australian radiation of the Egerniinae was well underway by the mid-Miocene.
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| The reassembled skull bones of Egernia gillespieae, a 15 million year old skink from Riversleigh World Heritage Area of northwestern Queensland. Remarkably similar to modern social skinks (silhouette shown) E. gillespieae instead is equipped with rounded crushing teeth and a deep, thick jaw. |
Egernia gillespieae, sp. nov.
Etymology:— Named in honor of researcher Dr. Anna Gillespie, who played a central role in the recovery and preparation of this specimen and countless other Riversleigh fossils.
Kailah M. Thorn, Mark N. Hutchinson, Michael Archer and Michael S. Y. Lee. 2019. A New Scincid Lizard from the Miocene of Northern Australia, and the Evolutionary History of Social Skinks (Scincidae: Egerniinae). Journal of Vertebrate Paleontology. e1577873. DOI: 10.1080/02724634.2019.1577873
Australian blue tongue lizard ancestor was round-in-the-tooth eurekalert.org/e/96XJ via @EurekAlert dropbox.com/s/kl1rsgmwxsk7zue/....
